Dry cell



R. L. GLOVER May 8, 1951 DRY CELL Filed Dec. 22, 1945 INVENTOR ROLANDL.GLOVER A ORNEY Patented May 8, 1951 DRY CELL Roland L. Glover,Lakewood, Ohio, assignor, by mesne assignments, to Union Carbide andCarbon Corporation, a. corporation of New York Application December 22,1945, Serial N 0. 636,835

29 Claims.

1 This invention relates to dry cells and has for an object to providesuch a cell having enhanced resistance to leakage. Another object is toprovide a dry cell having a number of factors tend ing to substantiallydelay any leakage tendency. In dry cells for flashlights and othercontainers, leakage of electrolyte outside of zinc forms a growingcrystalline mass in drying that clings to many types of surfaces and maycause bulging of the cell jacket until the cell sticks in the enclosure.One prior suggestion for overcoming this difiiculty has been theso-called metal jacket which adds weight in order to get the necessarystrength.

In contrast to that attempted solution, the present invention attainscomparable results without placing so much reliance upon the combinedweight and strength as does the iron jacket. A number of factorscontribute to this result in the present invention. One such factor isincreased gas space in the cell without reducing its elfective rating.Two additional gas spaces are provided that are not found in thecustomary commercial cell. One of these is an exudant chamber outside ofthe zinc and another is a long hole in the carbon to provide betterventing without lowering the resistance to liquid egress from the cell.Another factor has been a lighter weight resinous plastic jacket whichis electrolyte-proof, non-fibrous, and stiff enough not to bulge underany crystalline growth of electrolyte material. Such jacket is stiff andresistant in the sense that it maintains a high degree of mechanicalrigidity through its ability to resist penetration by the electrolyte,or any other effect by the electrolyte operating to decreasesignificantly it stifiness.

This application is a continuation-in-part of my prior applicationSerial No. 439,458 filed April 18, 1942 for Dry Cells and Process forManufacturing the Same" now Patent No. 2,396,693, dated March 19, 1946.

Referring to the drawing:

Fig. 1 is an elevational view of a construction in section showing oneembodiment of this invention;

Fig. 2 is a partial detail showing the device Fig. 1 with a reinforcedbottom;

Fig. 3 is a sectional view illustrating another embodiment of thisinvention having a short hole in the carbon and provided with absorbentmate rial between the jacket and zinc electrode;

Fig. 4 is a sectional view illustrating the exudant chamber without anyfilling, the cell being provided with another type reinforced bottom;v

Fig. 5 is a sectional detail showing a further type bottom reinforcing,spacing the jacket from the zinc.

This cell includes many customary features such as a zinc electrode Zsurrounding electrolyte material E and a depolarizing mix M around acentral carbon electrode C as illustrated in Fig. 1. Means are providedfor closing the ends of the cell including a metal cover D at the topand a bottom formed by the zinc electrode Z being extended across thebottom end. The usual insulating washer W may be provided, also themetal cap H over a carbon electrode. A blanket A of anti-tarnish paperor other thin, tough, sulphide-free paper is capable of reducing thelikelihood of short circuit from particles of mix breaking off. Theusual gas chamber G is formed at the upper end of the cell within whichis the usual top washer I? constituting a means for supporting thecarbon electrode. A vent hole I! is aligned with the hole or passage 40in the carbon electrode. The periphery of the metal cap H is providedwith a flange 16 carrying an insulating Washer 14 to prevent any shortcircuit between the metal cover D and the metal cap H. If desiredsealing material [8 is provided around this washer to protect the cellagainst prematurely drying out. These foregoing features are believedconventional elements of dry cell construction.

In the embodiment illustrated in Fig. 1 the jacket J both here and ineach .of .the other embodiments has its ends 20 .spun over the contactthe ends of the cell and prevent looseness of the cell in the jacket.Each of the embodiments illustrated may have a long or short passage 4.0in the carbon electrode. Where the embodiment shown in Fig. 1 has noreinforcement for the zinc bottom, the construction shown in Fig. ,2does have such a reinforcement. Although not believed necessary in anyof the embodiments illustrated, nevertheless some conventional typesealing material may be placed in the location B to insure greatermoisture proof-ness in any exudant chamber and reduce the tendency forelectrolyte material therein to .dry out. The construction of Fig. 2 isthe same as that of Fig. 1 except for the bottom reinforcement. It willbe noted the plate K as well as the bottom of the zinc havestrengthening ribs .21 which nest into one another as shown.

The metal cap K at the bottom in Figs. ,2 to 5 inclusive is contiguousthe .zinc at the bottom of the cell to mechanically reinforce the sameagainst bulging due to internal pressure. This a 3 cap is soldered tothe zinc or spot welded in the center portion and also around or inportions adjacent the periphery so that both bottom sheets willnecessarily have to move together in event of any fiexure. This bottomwhen of the shape as in Fig. 4 fits tightly over the end of the zinc.The metal reinforcing cap K is preferably of a metal less active thanzinc such as terneplate, tinplate, cadmium plated steel and the like sothat such cap is not attacked significantly so long as the zinc ispresent.

The embodiment illustrated in Fig. 3 is like that in Fig. 2 except forthe addition of a layer of absorbent material S such as the cellulosewadding or preferably absorbent paper. Absorbent paper is preferredmaterial. It assists in immobilizing any electrolyte expressed through aperforation in the zinc can by its absorbent effect. Creepage throughthe jacket is impossible due to its non-fibrous electrolyte-proofnature. The absorbent material may be waterproofed for a distance of toA" from the top and bottom of the cell.

Surrounding the zinc electrode Z in Fig. 4 for example is an exudantchamber X for any electrolyte material which may exude through the zincafter its corrosion. The outer wall of this exudant chamber isconstituted by a jacket J of insulating material which is non-fibrousand stiff enough when in contact with electrolyte material to preventcrystalline growth of such material from causing the jacket to bulge.The exudant chamber in Fig. 3 is shown as being filled to a large extentwith an absorbent material S such as highly absorbent paper or cellulosewadding whereas in Figs. 4 and 5 no suchabsorbent material is used. Whenabsorbent paper is used its top and bottom edge are preferablyimpregnated with a waterproofing material for an eighth to a quarter ofan inch. The ends 20 of the jacket J are spun over as illustrated in thedrawing for the purpose of making contact with the ends of the cellenough to prevent egress of electrolyte material. One difference betweenthe present construction and that shown in Patent No. 2,396,693, residesin elimination of the necessity for sealing material closing the ends ofthe exudant chamber X. It has been found that such sealing material isnot essential. The present invention permits reducing the load on suchsealing material so that it may be curtailedior-frequently eveneliminated. This is because the jacket J possesses initially, andmaintains even against the effect of contacting electrolyte, amplemechanical strength to hold an effective contact seal at both the upperand lower ends of the cell. However to provide greater moistureproofness in the exudant chamber such sealing material as is describedin said parent application may be used though not believed necessaryhere. Or if desired, a sealing material may be placed outside of themetal ends around the inner portion of the head in the locationdesignated by the letter B. The zinc at the bottom of the cell in Figs.2 to 5 inclusive is reinforced by a bottom cap K to prevent bulging, thezinc and the cap K having nesting engagement in strengthening ribs 2|illustrated.

As shown in Fig. 4 one or more holes 50 may be placed in the zincelectrode so that gas pressure inside the cell may beequalized withinthe cell and the exudant chamber thus removing any tendency for tensilestress to exist in the zinc due'to internal pressure. Similar holes maybe 4 used in each of the other embodiments illustrated if desired.

The total volume of gas space is about 15% of the total Volume of thecell and the relative volumes of the three gas chambers are about asfollows: the exudant chamber X about A; or roughly 33% of the gaschamber G; the full length bore 40 in the carbon electrode C is about 6%of the gas chamber G whereas the'short bore in Fig. 3 is only about 2%of the volume of the gas chamber G.

The construction of Fig. 4 has no filler within the exudant chamber sothat as electrolyte material tends to crystallize pressure between thestiff jacket and the zinc may tend to spread such electrolyte materialand thus reduce any tendency for the jacket to bulge. The reinforcingcap K has side portions which extend in between the jacket and zinc forspacing them apart at the bottom. The crimped joint between the metalcover D and the zinc electrode extends radially outward from the outersurface of the main body portion of the zinc to efiectively space thejacket and zinc at the top of the cell.

Fig. 5 is like Fig. 4 except that the reinforcing bottom K does not havethe axially extending side portions but merely is of large enoughdiameter to space the jacket from the zinc. The internestingstrengthening ribs 2| tend to axially position the bottom cap withrespect to the zinc and jacket.

The exudant chamber X has a two-fold function, one such function is toprovide additional gas space into which gas and exudant electrolytematerial may move radially to reduce pressure generated within the zincelectrode. Another function for the exudant chamber when combined with astiff jacket having an electrolyteproof inner surface is to providespace into which any exudant electrolyte material may spread so that itscrystalline growth on drying need not cause bulging of the jacket J.

The jacket or sleeve J is preferably thermoplastic material such as avinyl chloride polymer, vinyl chloride-acetate copolymer, celluloseacetate butyrate, ethyl cellulose or a thermo setting plastic such as aphenolic condensation product. In practice the jacket J is made ofcellulose acetate butyrate purchased under the trade name of Tenite II,a product of Tennessee Eastman Corporation having formula 205E withplasticity H. For the flashlight type dry cell the jacket including itsspun over ends is 2%" long uncurled and 2 /4 long over curled ends,having an inside diameter of 1.25" with its wall .020 thick. Itsphysical properties at 77 F. and 50% relative humidity are as follows:

Modulus of elasticity (1.33 to 1.67) x10 Specific gravity, 1.18 to 1.22

Tensile strength, 4300 to 6000 lbs., p. s. i. Flexure strength, 6300 to9700 lbs, p. s. i. Rockwell hardness, R to R114 This material is adaptedto absorb not more than 2% moisture on immersion in water for 24 hoursso that the material retains its stiffness whether in contact with themoist electrolyte material or not. The material being non-fibrous is notsubject to penetration between the fibers as is a material such aspaper. It is not particularly adapted to impede the creepage ofelectrolyte along its surface but does prevent it from creeping andwicking through the body of the material. The jacket is made in the formof a seamless tube and is adapted to receive printing and the 5 usualmarkings. The pressure generated within the cell does not cause eitherthe jacket J or the zinc Z to bulge since they are of cylindrical shapeand rather any such tendency is believed due to the growth ofcrystalline mass of electrolyte material, which is resisted by thejacket.

In the parent patent the jacket was anchored to the cell principally bythe sealing material at each end of the exudant space whereas in thepresent application the jacket makes a contact seal with the ends of thecell. Any pin hole or fracture in the film on the inside of the jacketin the parent case was in danger of causing the fibrous material toabsorb a large quantity of moisture from the electrolyte materialwhereas in the present case the jacket is non-fibrous and thereforeremoves the possibility of the behavior just described.

Having the carbon electrode pores partially impregnated with a waterrepellant material similar to the oil described in the patent to Chaney1,836,903 increases the resistance or impermeability of the carbon towater when the pores are f Chaneys capillary size. The passage or hole40 may extend the full length of the carbon as illustrated in Figs. 1, 2and 4 or such passage may extend only through at least a major portionof the space G above the depolarizer mix and electrolyte material. Thecarbon should be free of any transverse openings connecting with thehole 40 which are larger than the pores as otherwise resistance to waterpassing into the passage 40 might be objectionably lower. The functionof the passage 40 in the carbon electrode is primarily to lower theresistance of the carbon to the escape of gas since the path for gastransversely through the pores is shorter than would be the case if thepassage 40 were not present. For reducing gas pressure in the passage 40gas is vented through opening l2. A second function for the passage 40is to serve as an additional gas chamber since the larger the total gasspace within the cell the longer will be the delay necessary for anypressure generated within the cell to rise objectionably high under themost adverse conditions. From the standpoint of its venting function thepresence of depolarizing mix getting into the passage 40 duringinsertion of the carbon into the mix is not objectionable but from thestandpoint of the passage 40 being a gas chamber whose volume added tothe volume of the gas chamber G and the volume of the exudant chamber X,increases the total volume available for holding gas, it may bedesirable to keep out the depolarizing mix by use of a small washer overthe end of the carbon on being moved into the depolarizing mix. Afive-fold reduction in resistance to gas venting is achieved.Accordingly an original stock having only /5 the water or gaspermeability of the solid stock may be used when an electrode havin apassage 40 is adopted. The time to incidence of electrolyte leakage fromthe vent hole I2 is longer by threefold or more when the hollowelectrode illustrated is used instead of the solid electrode of the samestock. The full length passage 40 in the electrode also functions as atrap for electrolyte material which may become filled under pressure.The electrolyte may evaporate as rapidly as it comes to the surface ofthe passage or hole 40 in the carbon electrode, leaving a porous layerof crystals. If the electrolyte reaches the inner surface of theelectrode faster than evaporation takes place it may spread over suchinner surface without being forced out from the vent hole. It

- present invention does from the vent hole l2 when a hollow electrodeis used than when the electrode is solid. This time element may beprolonged to client the overall safety factor of the cell againstleakage. With the described invention the total available pressurerelieving gas spaces is increased almost 30% with no decrease in theamount of active cell ing'redients. The possibility of making a carbonmore dense OiTels greater resistance to the escape of liquid withoutincreasing the resistance to gas being vented.

Where the parent patent sought to prevent bulging of the jacket bysealing material around the top and bottom of the exudant chamber, thenot contemplate the need for the same degree of moisture proofness sincethe jacket J is stiff enough to resist outward bulglng under any localgrowth of electrolyte material and possesses strength to hold anefiective pressure seal contact at both ends of the cell. Where theconstruction of the parent Patent 2,396,693 tended to impede thespreading of electrolyte by strands of spacing material, the presentinvention regards the spreading of electrolyte within the exudantchamber to be less objectionable when the non-bulging jacket may makesome spreading necessary. The ends of the jackets are both preferablyspun over after the same is in place on the cell. While not shown inFig. 1 it will be understood that greater resistance to leakage isobtained when an absorbent paper wrap is placed between the jacket andthe zinc. Such paper has not been illustrated because it need not be ofas great, thickness as is illustrated in Fig. 3. However, the variant ofthe construction shown in Fig. 1 with this paper present is preferred tothat illustrated. There is then an exudant chamber present though ofreduced thickness. As stated before when such thinner absorbent paper isused its ends are impregnated with a electrolyte and water proofingmaterial for an eighth to a quarter of an inch from each edge. Suchconstruction is equivalent to the use of a thinner absorbent sheet thanthat which is shown in Fig. 3. I

Among the advantages of this invention may be mentioned the provision oftotal volume of gas chambers being larger due to the bore in the carbonelectrode and to the exudant chamber outside the zinc, without reducingthe effective quantity of active elements and materials. The greater thetotal volume of gas spaces, the longer will be deferred the generationof any objectionably large pressures within the cell under extremeconditions. The non-fibrous still sleeve is strong enough when wet toresist bulging due to the growth of electrolyte material. The absorbentmaterial in Fig. 3 possesses the advantages pointed out previously. Thevent I2 aligned with the bore in the carbon electrode is suincient tovent any pressure in all three gas chambers, especially after the zinchas been corroded or when the zinc is provided with hole 50. Thereinforced bottom plate K is plated with an appropriate material whichdoes not react with the zinc and electrolyte present. The hollow carbonelectrode is more permeable to gas venting due to the short path for thegas to travel, and accomplishes this without reducing the resistance topassage of liquid through the pores of the carbon.

By having the cell capable of venting gas pressure, the jacket need beonly stifi enough not to bulge under growth of electrolyte material incrystallizing and drying, or still enough to spread the electrolytematerial and enable any such growth to occupy a greater area. It is notcertain but possible that-such growth of the electrolyte incrystallizing may occur inwardly instead of outwardly. Also, when gas isvented from the exudant chamber between the zinc and jacket, then morespace in this chamber may be occupied by exudant electrolyte materialthan would be the case if compressed gas impeded the spread of any suchelectrolyte material. I In other words, with this invention the plasticjacket may be made lighter than has heretofore been possible and theexudant chamber more effective as an expansion spaced for electrolytematerial.

The jacket illustrated herein as being provided with spun-over ends isclaimed in the co-pending application of A. P. Drummond, Serial No.667,768, filed May 7, 1946, for Dry Cell, to obtain a good fit for thejacket without any looseness longitudinally between the cell and jacket.

'I claim:

1. A dry cell combination of an electrolyte material, adepolarizing mix,a central electrode within the mix and electrolyte material, an outerelectrode outside the electrolyte material and mix, means closing theends of the cell, a principal means for venting gas pressure within thecell through a cell wall, of a carbonaceous electrode containing a waterrepellent material, having capillary pores but being free of anytransverse openings larger than its pores, and having a longitudinalbore, said carbonaceous electrode constituting a principal gas ventingdevice which is more resistant to the passage of electrolyte materialthan to the passage of gas from the cell, whereby gas may be ventedgenerally radially through at least a portion of said carbonaceouselectrode wall without substantially reducing the resistance of the cellwall to the passage of liquid within the cell out through said cellwall, and a resinous plastic jacket outside the outer electrode and ofelectrolyte-proof material which is non-bulging when in contact withelectrolyte material or its crystalline growth, said jacket havingportions bent over each end of the cell.

2. A flashlight-type dry cell having a central electrode, depolarizing.mix around said electrode, electrolyte material surrounding the mix, anouter electrode outside the electrolyte material, means closing each endof the cell and the improvement comprising in combination, acarbonaceous electrode containing a water repellent material,having'capillary pores but being free of any transverse openings largerthan its pores, having a longitudinal bore, said electrode constitutinga principal gas venting device which is more resistant to the passage ofelectrolyte material than to the passage of gas, whereby gas may bevented generally radially through at least that portion of saidcarbonaceous electrode which is above the electrolyte and depolarizingmaterials, and a jacket outside the outer electrode of cellulose acetatebutyrate having a specific gravity between 1.18 and 1.22, a tensilestrength of 4300 to 6000 pounds per square inch, a modulus of elasticityof around (1.33 to l.67) l0 a Rockwell hardness of R95 to R114, afiexural strength of 6300 to 9700 pounds per square inch, adapted toabsorb not more than 2% moisture on immersion in water for 24 hours, andwhich is not adapted to bulge under growth of electrolyte material incrystallizing and drying when not substantially thicker than .020 inch.

3. A dry cell having a central electrode, depolarizing mix around saidelectrode, electrolyte material outside themix, an outer electrodesurrounding the electrolyte material, means for closing each end of thecell, a gas chamber between said end closing means but beyond saidelectrolyte material and depolarizing mix, and the improvement forenhancing the leakproof character of the cell by an increase in gasspace in which expansion may occur which comprises a second gas chamberhaving longitudinal walls extending adjacent the first and separatedfrom the first mentioned gas chamber by one or said electrodes which isgas permeable, a gas vent from one of said chambers, and said gaspermeable electrode being constructed to oppose the passage ofelectrolyte material therethrough.

4. A dry cell having a central carbon electrode, an electrolytematerial, a depolarizing mix between the central carbon electrode andthe electrolyte material, a zinc electrode surrounding electrolytematerial, means for closing the ends of the cell, a gas chamber betweenthe zinc and carbon electrodes within the end closing means and beyondthe electrolyte material and depolarizing mix, the improvement inventing such cell which comprises the carbon electrode being partiallyimpregnated with a water repellant material, having a porosity adaptedfor gas venting radially therethrough, having an axial bore of a lengthand size capable of greatly reducing the resistance of the carbon to thepassage of gas radially into the bore, and being substantially free oftransverse gas passages through the walls of the carbon which aresubstantially larger in size than the pores of the carbon, and a ventedmetal cap extending over the bore in an end portion of the carbonelectrode whereby gas venting into the bore and out of said cap isfacilitated.

5. A dry cell having a central porous carbon electrode, an electrolytematerial, a depolarizing mix between the central carbon electrode andthe electrolyte material, a zinc electrode around the electrolytematerial, means for closing the ends of the cell, a gas chamber at oneend portion of the cell between the zinc and carbon electrodes, betweenthe end closing means and beyond the electrolyte material anddepolarizing mix, an exudant chamber outside the zinc provided with anouter wall substantially uniformly spaced from the zinc and having aninner surface of electrolyte-proof material, means for closing the endsof said exudant chamber, said carbon electrode having a hollow axis ofsubstantial length and size to constitute an expansion chamber whosevolume added to the volume of the exudant chamber and said gas chamberis effective to delay substantially a pressure increase tending torupture the cell, the carbon electrode having walls free of anytransverse passages larger than its pores and being at least partiallyimpregnated with a water resistant material.

6. A dry cell having a zinc electrode around an electrolyte material, acentral carbon electrode, a depolarizing mix between the carbonelectrode and the electrolyte material, means for closing the ends ofsaid cell, a gas chamber at one end of the cell within the adjacent endclosing means but beyond the electrolyte material and depolarizing mix,the improvement in venting the gas chamber through the pores of thecarbon electrodes which comprises the carbon electrode being providedwith a substantially axial bore of a size and length to lower theresistance of the electrode to about 20% of the resistance an electrodeofiers to the passage of gases therethrough when of the same porositybut without such bore,

8 the electrode except for such bore being free of holes between-thebore and the outside which are substantially larger than its pores.

7. A dry cell having a .depolarizing mix, a carbon electrode within saidelectrolyte material surrounding the mix, a zinc electrode around theelectrolyte material, means closing each end of the cell, a gas chamberwithin one end closing means but beyond the electrolyte material anddepolarizing mix, and the improvement for increasing the leakproofcharacter of the cell by increasing the volume of .gas .space whichcomprises said carbon electrode being provided with a longitudinal holetherein constituting a second gas chamber of a length to extend at leastthrough a major part of the depth of said first mentioned gas chamber,.said carbon electrode being permeable to gas .transversely of said holebut free of transversely extending holes larger than its pores andconnected with said longitudinal hole and said carbon electrode havingbeen treated at least in the longitudinal portion thereof containingsaid hole to increase the water resistant character of its pores wherebygas may be vented by a short radial path into said longitudinal holewithout increasing the danger of leakage of electrolyte material.

.8. A dry cell having a depolarizing mix, a carbon electrode within saidmix, electrolyte material surrounding the mix, a zinc electrode aroundthe electrolyte material, means closing each end of the cell, a gaschamber between said end closing means but beyond the electrolytematerial and depolarizing mix, and the improvement for increasing theleakproof character of the cell by increasing the volume of gas spacewhich comprises said carbon electrode being provided with a longitudinal,hole therein constituting a second gas chamber of a length to extend atleast through a major part of the depth of said first mentioned gaschamber, said carbon electrode being permeable to gas transversely ofsaid hole but free of transversely extending holes larger than its poresand connected with said longitudinal hole and said carbon electrodehaving been treated at least in the longitudinal portion thereofcontaining said hole to increase the water resistant character of itspores whereby gas may be vented by a short radial path into saidlongitudinal hole without increasing the danger of leakage ofelectrolyte material, an exudant chamber outside of said zinc electrodeand closed by an outer wall having an electrolyte proof inner surfacethe ends of said exudant chamber being closed against free egress of anyelectrolyte material therein, and a vent for gas from the longitudinalhole to the outside of the cell.

9. A dry cell having a depolarizing mix, a central electrode within saidmix, electrolyte material surrounding the mix, an outer electrode aroundthe electrolyte material, means closing .each end of the cell, a gaschamber between said end closing means but beyond the electrolytematerial and depolarizing mix, and the improvement for increasing theleakproof character of the cell by increasing the volume of gas spacewhich comprises said central electrode being provided with alongitudinal hole therein constituting a second gas chamber of a lengthto extend at least through a major part of the depth of said firstmentioned gas chamber, said central electrode being permeable to gastransversely of said hole, an exudant chamber outside of said outerelectrode and closed by an outer wall having an electrolyte proof innersurface, the ends of said exudant chamber being closed against freeegress of any electrolyte material therein, and a gas vent from at leastone of the three mentioned chambers to the outside of said cell.

10. A dry cell having a central electrode, depolarizing mix around saidelectrode, electrolyte material surrounding the mix, an outer electrodeoutside the electrolyte material, means closing each end of the cell,and the improvement comprising in combination, a carbonaceous electrodecontaining a water repellent material having capillary pores but beingfree of any transverse openings larger than its pores, having alongitudinal bore, said electrode constituting a principal gas ventingdevice which is more resistant to the passage of electrolyte materialthan to the passage of gas, whereby gas may be vented generally radiallythrough at least that portion of the carbonaceous electrode which isabove the electrolyte material and the depolarizing mix, and a jacketforming an exudant chamber outside the outer electrode with an outerwall for said chamher being non-bulging under the growth of anycrystalline dried electrolyte material in .said chamber, the innersurface of said wall being non-fibrous, electrolyte proof and ofelectrical insulating material.

11. A dry cell having a depolarizing mix, a central electrode withinsaid mix, electrolyte material around the mix, an outer electrodesurrounding the electrolyte material, means for closing the .ends of thecell, a jacket of non-fibrous insulating material outside the outerelectrode and cooperating with the end closing means 'by having its endsspun over to form beads in contact with the end closing means, saidjacketbeing electrolyte proof and non-bulging under the growth ofcrystallizing electrolyte material contiguous said jacket, a metalbottom reinforcing an outer electrode bottom against bulging, andnesting strengthening ribs on both the reinforcing metal bottom andouter electrode bottom, said metal bottom being held against the outerelectrode by said jacket.

12. A dry cell having a depolarizing mix, a central electrode withinsaid mix, electrolyte material around the mix, an outer electrodesurrounding the electrolyte material, means for closing the ends of thecell, a carbon electrode containing a water repellent material havingcapillary pores but being free of any transverse openings larger thanits pores, having a longitudinal bore, said electrode constituting aprincipal gas venting device which is more resistant to the passage ofelectrolyte material than to the passage of gas, whereby gas may bevented generally radially through at least a portion of said carbonelectrode, and a jacket of non-fibrous insulating material outside theouter electrode having at least one end spun over to form a beadcooperating with and contacting that end closing means, said jacketbeing electrolyte proof and non-bulging under the growth ofcrystallizing electrolyte material contiguous said jacket, a metalbottom having its periphery spacing the outer electrode from saidjacket.

13. A dry cell having a depolarizing mix, a carbon electrode within saidmix, electrolyte material surrounding the mix, a zinc electrode aroundthe electrolyte material, means closing each end of the cell, a gaschamber between said end closing means but beyond the electrolytematerial and depolarizing mix, and the improvement for increasing theleakproof character of the cell by increasing the volume of gas spacewhich comprises said carbon electrode being provided with a longitudinalhole therein constituting a second gas chamber extending the full lengthof said carbon electrode, said carbon electrode being permeable togas-transversely of said hole but free of any transversely extendingholes larger than its pores and connected with said carbon elec trode,and said carbon electrode having been treated to increase the waterresistant character of its pores, means closing an end of said carbonelectrode within the cell to prevent depolarizing mix or electrolytematerial filling said longi-. tudinal hole.

14. A dry cell having a central electrode, depolarizing mix around theelectrode, electrolyte material surrounding the mix, an outer electrodeoutside the electrolyte material, means for closing each end of thecell, a gas chamber between said end closing means but beyond saidelectrolyte material and depolarizing mix, a principal gas vent fromsaid chamber through a carbonaceous electrode containing a waterrepellent material, having capillary pores but being free of anytransverse openings larger than its pores, having a longitudinal bore,said electrode constituting jsaid'principal gas venting device and beingmore resistant to the passage of electrolyte material than to thepassage of gas, whereby gas may be vented generally radially through atleast a portion of said carbonaceous electrode, and the improvement forenhancing the tendency of the cell to resist leakage of electrolytematerial comprising an exudant chamber outside the outer electrode, theouter wall of said exudant chamber being non-bulging due to the growthof any crystalline electrolyte material in said exudant chamber, havingan inner surface which is non-fibrous and electrolyte proof, and theends of said exudant chamber being closed against the free passage ofelectrolyte material, the outer wall of said exudant chamber beingspaced from the outer electrode in at least one end of the cell by ametal spacer between them.

15. A dry cell having a central electrode, depolarizing mix around saidelectrode, electrolyte material surrounding the mix, an outer electrodeoutside the electrolyte, means for closing the ends of the cell, and theimprovement in enhanced leakproofness which comprises in combination, acarbonaceous electrode containing a water repellent material havingcapillary pores but being free of any transverse openings larger thanits pores, having a longitudinal bore, said electrode constituting aprincipal gas venting device which is more resistant to the passage ofelectrolyte material than to the passage of gas, whereby gas may bevented generally radially through at least that portion of saidcarbonaceous electrode which is above the electrolyte and depolarizingmaterials, a stifi jacket outside the outer electrode, and an exudantchamber between the outer electrode and jacket, said chamber being freeof material which impedes the spreading of an exudant electrolytematerial in said chamber.

16. A dry cell comprising inner and outer electrodes with electrolytematerial and depolarizing mix therebetween, means for closing the endsof the cell, a device constituting a principal gas vent from said cellthrough a carbonaceous electrode containing a water repellent material,said electrode having capillary pores but being free of any transverseopenings which are larger than its pores, having a longitudinal bore,and being more resistant to the passage of electrolyte material than tothe passage of gas from said cell,

a jacket of non-fibrous insulating material nonbulging under growth ofcrystalline electrolyte material between the jacket and outer electrodeand having its end spun over the end closing means forming a bead ateach end of the cell, said outer electrode and jacket being spaced apartin at least a portion of their length, and absorbent material betweensaid jacket and outer electrode extending throughout at least a majorportion of the length of the cell, a crimped joint between one endclosing means and the outer electrode for spacing the jacket from theouter electrode adjacent said joint.

17. A dry cell comprising a central electrode, and an outer cylindricalelectrode, depolarizing mix and electrolyte material therebetween, meansclosing the ends of said cell, a gas vent for the cell, and a resinousplastic jacket surrounding the outer electrode and spaced therefrom inat least a portion of its length to provide an exudant chamber intowhich electrolyte material may move when it has penetrated through theouter electrode, said jacket being non-bulging due to any exudantelectrolyte material in drying by causing such material to spread withinsaid exudant chamber while growing, yet said jacket being substantially.02 inch in thickness whereby it is not substantially more still than isenough to efiect said spreading, and a compact cell is provided withample space for active cell ingredients.

18. A dry cell comprising a central electrode, andan outer cylindricalelectrode, depolarizing mix and electrolyte material therebetween, meansclosing the ends of said cell, a gas vent for the cell, and a resinousplastic jacket surrounding the outer electrode and spaced therefrom inat least a portion of its length to provide an exudant chamber intowhich electrolyte material may move when it has penetrated through theouter electrode, said jacket being non-bulging due to any exudantelectrolyte material in drying by causing such material to spread withinsaid exudant chamber while growi g, yet said jacket being notsubstantially more than .02 inch in thickness whereby it is notsubstantially more stifi than is enough to effect said spreading, and acompact cell is provided with ample space for active cell ingredients,said jacket being spaced from the outer electrode adjacent at least oneend by a crimped joint between the outer electrode and one end closingmeans.

19. In a dry cell having a central electrode, an outer electrode,depolarizing mix and electrolyte material between said electrodes, andmeans c1osing the ends of the cell, the combination therewith of theimprovement enhancing the leakproof character of the cell as well as itslightness in weight, compactness, and non-bulging character, saidimprovement comprising in combination a carbonaceous electrodecontaining a water repellent material having capillary pores but beingfree of any transverse openings larger than its pores, having alongitudinal bore, and said carbonaceous electrode constituting aprincipal venting device for gas in communication with the interior andexterior of the cell and offering greater resistance to egress ofelectrolyte material than to the passage of gas from said cell, anelectrolyte-proof resinous plastic jacket surrounding the outerelectrode for substantially its full length, and means closing the endsof any space between the jacket and outer electrode, whereby said jacketmay be made thin and only stiff enough not to bulge under thecrystalline growth of any electrolyte material in drying and need not bethick to resist bulging due to pressure of entrapped gas.

20. A dry cell according to claim 19 in which said jacket has its endsbent over the cell end closing means to constitute the means closing theends of any space between the jacket and outer electrode.

21. A dry cell according to claim 19 in which an expansion space isprovided between the jacket and outer electrode.

22. In a dry cell having a central electrode, an outer electrode,depolarizing mix and electrolyte material between said electrodes, andmeans closing the ends of the cell, the combination therewith of theimprovement enhancing the leakproof char: acter of the cell as well asits lightness in weight and non-bulging character, said improvementcomprising in combination a carbonaceous electrode venting device forgas in communication with the interior and exterior of the cell andoffering greater resistance to egress of electrolyte material than tothe passage of gas from said cell, an electrolyte-proof resinous plasticjacket surrounding the outer electrode for substantially its fulllength, and means closing the ends of any space between the jacket andouter electrode, whereby said jacket may be made thin and only stiifenough not to bulge under the crystalline growth of any electrolytematerial in drying and need not be thick to resist bulging due topressure of entrapped gas, said venting device being constituted by theinner electrode being of carbon partially impregnated with a waterrepellent material, said carbon electrode having a porosity adapted forgas venting radially therethrough, having a longitudinal recess of alength and size capable of greatly reducing the resistance of the carbonto the passage of gas radially into said recess and being substantiallyfree of transverse gas passages through the walls of said recess whichare substantially larger in size than the pores of the carbon, and avented cap extending over said longitudinal recess in an end portion ofthe carbon electrode, whereby gas venting into said recess and outthrough said cap is facilitated.

23. A dry cell according to claim 19 in which said jacket has athickness of about .02".

24. A dry cell having a central carbon electrode, an electrolytematerial, a depolarizing mix be tween the central carbon electrode andthe electrolyte material, a zinc electrode surrounding electrolytematerial, means for closing the ends of the cell, a gas chamber betweenthe zinc and carbon electrodes within the end closing means and beyondthe electrolyte material and depolarizing mix, the improvement inventing such cell which comprises the carbon electrode being impregnatedwith a water repellant material, having a porosity adapted for gasventing radially therethrough, having an axial bore of a length and sizecapable of greatly reducing the resistance of the carbon to the passageof gas radially into the bore, and being substantially free oftransverse gas passages through the walls of the carbon which aresubstantially larger in size than the pores of the carbon, and a ventedcap extending over the bore in an end portion of the carbon electrodewhereby gas venting into the bore and out of said cap is facilitated.

25. In a dry cell having an inner electrode and an outer electrode,depolarizing mix and elec-- trolyte material between said electrodes,and means closing the ends of the cell, the combination therewith of theimprovement enhancing the leakproof character of the cell, saidimprovement including the combination of a carbonaceous electrodecontaining a waterrepellent material having capillary pores but beingfree of any transverse openings larger than its pores, having alongitudinal bore, and said carbonaceous electrode constituting aprincipal venting device for gas in communication with the interior andexterior of the cell and ofiering greater resistance to the egress ofelectrolyte material than to the passage of gas from said cell, a jacketoutside of the outer one of said electrodes for substantially its fulllength and spaced from the outer electrode to provide an expansionchamber for any electrolyte material that may exude through that outerelectrode, and means closing the ends of said expansion chamber againstegress of electrolyte material, the inner face of said jacket with whichany exudant electrolyte material may come in contact having anelectrolyte-proof surface.

26. A dry cell according to claim 25 in which an absorbent material isplaced in said expansion chamber to facilitate the spread of any exudantelectrolyte material therein.

27. A dry cell according to claim 25 in which a carbon electrode ispartially impregnated with a water repellant material, has a porosityadapted for venting gas therethrough and is substantially free of anytransverse gas passages through the walls of the carbon which aresubstantially larger in size than the pores of the carbon.

28. In a dry cell having an inner electrode and an outer electrode,depolarizing mix and electrolyte material between said electrodes, andmeans closing the ends of the cell, the combination therewith of theimprovement enhancing the leakproof character of the cell, saidimprovement including the combination of a carbonaceous electrodeventing device for gas in communication with the interior and exteriorof the cell and offering greater resistance to the egress of electrolytematerial than to the passage of gas from said cell, a jacket outside ofthe outer one of said electrodes for substantially its full length andspaced from the outer electrode to provide an expansion chamber for anyelectrolyte material that may exude through that outer electrode, andmeans closing the ends of said expansion chamber against egress ofelectrolyte material, the inner face of said jacket with which anyexudant electrolyte material may come in contact having anelectrolyte-proof surface, said carbon electrode being centrallyarranged and provided with a longitudinal bore at least above thedepolarizing mix and electrolyte material, said longitudinal bore beingof a size and length capable of reducing the resistance of the carbon tothe passage of gas transversely into said bore from the inside of thecell, and a vented cap extending over said bore in an end portion of thecarbon electrode whereby gas venting into said bore and out through thecap is facilitated.

29. A dry cell according to claim 25 in which said jacket is still. toresist bulging by growth of electrolyte material in drying in saidexpansion chamber.

ROBERT L. GLOVER.

(References on following page) REFERENCES CITED Number The followingreferences are of record in the file of thls patent. 2,399,089 UNITEDSTATES PATENTS 6 2,410,826 Number Name Date 2,411,272 743,337 Schauli eta1 Nov. 3, 1903 2,440, 0 1,039,949 Jaeger Oct. 1, 1912 1,184,135Rudolphs May 23, 1916 1,481,145 Pepper Jan. 15, 1924 10 Number 1,336,903Chaney Dec. 15, 1931 372,875 1,925,374 Deibel Sept. 5, 1933 438,6631,990,463 Reinhardt Feb. 5, 1935 2,079,495 Deibel May 4, 1937 2,198,423Anthbny Apr. 23, 1940 5 70 2,262,837 Deibel Nov. 18, 1941 page 2,315,592Cargill Apr. 6, 1943 Name Date McEachron et a1. Oct. 19, 1943 Anthony eta1. Jan. 8, 1946 Anthony Apr. 23, 1946 Lang et a1. Nov. 12, 1946 KellerNov. 19, 1946 Hirtle Apr. 27, 1948 FOREIGN PATENTS Country Date GreatBritain May 19, 1932 Great Britain Nov. 18, 1935 OTHER REFERENCESCarswell et 2.1., Electrical World, June 12, 1943,

1. A DRY CELL COMBINATION OF AN ELECTROLYTE MATERIAL, A DEPOLARIZINGMIX, A CENTRAL ELECTRODE WITHIN THE MIX AND ELECTROLYTE MATERIAL, ANOUTER ELECTRODE OUTSIDE THE ELECTROLYTE MATERIAL AND MIX, MEANS CLOSINGTHE ENDS OF THE CELL, A PRINCIPAL MEANS FOR VENTING GAS PRESSURE WITHINTHE CELL THEOUGH A CELL, WALL, OF A CARBONACEOUS ELECTRODE CONTAINING AWATER REPELLENT MATERIAL, HAVING CAPILLARY PORES BUT BEING FREE OF ANYTRANSVERSE OPENINGS LARGER THAN ITS PORES, AND HAVING A LONGITUDINALBORE, SAID CARBONACEOUS ELECTRODE CONSTITUTING A PRINCIPAL GAS VENTINGDEVICE WHICH IS MORE RESISTANT KTO THE PASSAGE OF ELECTROLYTE MATERIALTHAN TO THE PASSSGE OF GAS FROM THE CELL, WHEREBY GAS MAY BE VENTEDGENERALLY RADIALLY THROUGH AT LEAST A PORTION OF SAID CARBONACEOUSELECTRODE WALL WITHOUT SUBSTANTIALLY REDUCING THE RESISTANCE OF THE CELLWALL TO THE PASSAGE OF LIQUID WITHIN THE CELL OUT THROUGH SAID CELLWALL, AND A RESINOUS PLASTIC JACKET OUTSIDE THE OUTER ELECTRODE AND OFELECTROLYTE-PROOF MATERIAL WHICH IS NON-BULGING WHEN IN CONTACT WITHELECTROLYTE MATERIAL OR ITS CRYSTALLINE GROWTH, SAID JACKET HAVINGPORTIONS BENT OVER EACH END OF THE CELL.